Horizontal and vertical gaseous hydrocarbon wells may accumulate liquids within a wellbore conduit thereof. These liquids may slow, resist, block, and/or occlude flow of a wellbore fluid stream within the wellbore conduit, thereby decreasing a production rate of the wellbore fluid stream from the wellbore conduit. This especially may be true late in the lifetime of the gaseous hydrocarbon well and/or after the production rate of the wellbore fluid stream decreases below a threshold production rate.
A gas-dominated well can be significantly advantaged by the employment of a cyclic plunger when flow rates have dropped below the critical lifting velocity. The plunger provides a barrier that inhibits gas breakthrough of the liquid slug or column. The differential pressure created by this inhibiting action assists the well in lifting liquids to the surface with lower gas velocities than those normally reached. This mitigates the cost of installing smaller internal diameter tubing to increase the gas velocity.
Plungers typically “rest” at the surface in a lubricator or section of pipe above the wellhead valves. The lubricator can drop the plunger into the well on an as needed basis, as determined by surface measurement and gauges. The well is normally shut in to allow the plunger to fall. After a sufficient measured (estimated) time, the well is allowed to produce again in hopes of returning the plunger back to surface along with liquids that have slowed or stopped gas production with their attendant hydrostatic weight.
A common goal for an optimized plunger lift system is the reduction of the hydrostatic head applied to the producing formation to the minimum flow impediment possible. Thus, optimization of the number of runs the plunger makes in a given period is desirous. However, actual downhole plunger velocities are unknown with current surveillance tools. Instead, average plunger velocity is determined from the plunger drop/receive cycle times. Incomplete plunger velocity information leads to less effective optimization and potential safety hazards from catastrophic collisions in the plunger lift lubricator when there is a “dry trip” (e.g., the plunger returns to surface without a cushioning fluid buffer ahead of it).
Thus, there exists a need for systems and methods to obtain real-time plunger velocities and other performance data of interest to improve plunger lift operations.